In general, as a formation method of wiring of a semiconductor device, a sputtering (low-temperature sputtering) method for depositing an aluminum material at a temperature of below 300.degree. C. is used. Recently, with the spread of microstructures of semiconductor devices, there may occur an accident of open-circuit due to insufficient filling of aluminum material in a wiring connection hole.
As means for solving such a problem, a reflow method in which an aluminum material is deposited by sputtering while keeping a semiconductor device at about room temperature and then heated to above 500.degree. C., and a high-temperature sputtering in which an aluminum material is deposited by sputtering while keeping a semiconductor device at above 400.degree. C. are known to be capable of filling an aluminum material in a fine wiring connection hole or a wiring groove
The prior art reflow method and high-temperature sputtering method have respective problems. First, in the reflow method, after an aluminum material required for filling a wiring connection hole or a wiring groove is deposited at a temperature of below 100.degree. C., in the state where the deposition is of discontinued, heated to a temperature of above 500.degree. C. in the state of staying on the semiconductor device to remelt the aluminum material deposited on the semiconductor device, thereby moving the aluminum material to fill in the wiring connection hole or the wiring groove. However, when a wiring comprising an aluminum material is buried in the underlayer, this method has a danger of causing plastic deformation of the buried wiring by heating to above 500.degree. C., resulting in a malfunction.
In the high-temperature sputtering method, on the other hand, after a low-temperature sputtering aluminum layer is previously formed by depositing an aluminum material by sputtering (low-temperature sputtering) at a temperature of below 100.degree. C., followed by sputtering deposition of an aluminum material at a temperature of above 400.degree. C. (high-temperature sputtering), thereby filling the wiring connection hole or the wiring groove. However, in order to fill in the wiring connection hole when performing sputtering (high-temperature sputtering) at above 400.degree. C., a film thickness (B) of high-temperature sputtering has been larger than a film thickness (A) of low-temperature sputtering.
However, under the above conditions, there may be a case that the shape of a registration accuracy measurement mark is destructed by heat treatment at high-temperature sputtering.
The registration accuracy measurement mark is a mark (shape) for measuring a registration accuracy of pattern used in each photolithography process, and when the wiring connection hole (or the wiring groove) is filled when forming a wiring with an aluminum material, the aluminum material is also deposited on the registration accuracy measurement mark as well. At this moment, since the shape is destructed by heat treatment in the above case, there may occur a problem in that the registration accuracy cannot be known exactly.
In the case of A&gt;B, on the contrary, heat treatment at high-temperature sputtering is insufficient, filling of fine wiring connection hole is imperfect, and a gap tends to be generated, which is a problem in reliability.
Further, even when the depth of the connection hole is shallowed by providing a plug, in a stacked structure or the like where two connection holes are piled up, there is a problem in that a hollow tends to generate. If a high-temperature condition is used or high-temperature sputtering is performed to prevent generation of such a hollow, the shape of the registration accuracy measurement mark is destructed as in the above-described case, and the registration accuracy cannot be known exactly.